Use of PP-g-MA prepared by solution process as compatibilizerin polypropylene/polyamide 6 blends

บทคัดย่อ

In this work, polypropylene grafted maleic anhydride (PP-g-MA) prepared by solution process was used as a compatibilizer for polypropylene (PP)/polyamide 6 (PA6) blends. PP with melt flow index (MFI) of 10 g/10 min was grafted with maleic anhydride (MA) using benzoyl peroxide (BPO) as an initiator and toluene as a solvent. The effects of BPO and MA concentration on the grafting degree of MA onto PP were studied. The grafting degree was determined by a back-titration procedure whereas the formation of graft copolymers was confirmed by FT-IR technique. It was found that the maximum extent of grafting achieved was 0.87%. Blend of PP (MFI of 25 g/10 min) and PA6 with weight ratio of 70/30 was prepared by twin screw extruder. The prepared PP-g-MA (0.87% grafting) was used as a compatibilizer at the amount of 5 and 10 parts per hundred of the blend. The testing specimens were prepared by injection molding machine. The results showed that the tensile strength of the compatibilized blends was substantially higher than that of the uncompatibilized blend whereas percent elongation and Young’s modulus were comparable. Morphology of the blends investigated by SEM technique disclosed that the compatibilized blends exhibited a remarkable decrease in size of the dispersed domain. TGA and DSC were employed to investigate thermal behaviors of the blends. PP-g-MA had a slight influence on the thermal stability of the blends. The crystallization rate of PP in the blends was higher than that of the neat PP. On the contrary, the presence of PP reduced the crystallization rate of PA6 in the blends.